1. Field of the Invention
The present invention relates to a thermal printer including a thermally activating apparatus for a heat-sensitive adhesive sheet having a heat-sensitive adhesive layer that exhibits a non-bonding property normally and expresses a bonding property by heat on one side of a sheet-like substrate, and more particularly, relates to a technique capable of efficiently driving a printing thermal head and an activating thermal head with limited allowable electric power.
2. Description of the Related Art
Heat-sensitive adhesive sheets (heat-sensitive adhesive labels) as one type of so-called linerless labels have recently been used in broad areas, such as adhesion of POS labels for food, distribution/delivery labels, medical labels, baggage tags, and indicator labels for bottles and cans. The heat-sensitive adhesive labels are constructed such that a heat-sensitive adhesive layer which exhibits a non-bonding property normally and expresses a bonding property by heat is formed on the back of a sheet-like label substrate (for example, base paper) and a printable plane is formed on the front surface.
The heat-sensitive adhesive has a thermoplastic resin, a solid plasticizer or the like as the main component, and exhibits a non-bonding property normally but expresses a bonding property by being activated when heated with a thermally activating apparatus. The activating temperature is normally from 50 to 150xc2x0 C., wherein in this temperature range, the solid plasticizer in the heat-sensitive adhesive melts to give a bonding property to the thermoplastic resin. The melted solid plasticizer is gradually crystallized through a supercooled state; thus, the bonding property is maintained for a fixed period of time. While the bonding property is maintained, the adhesive label is used in the manner of being adhered to the object such as a glass bottle.
The printable plane of the heat-sensitive adhesive label is composed of, for example, a heat-sensitive color-forming layer, on which a desired character or image is printed with a thermal printer having a general thermal head; thereafter, the heat-sensitive adhesive layer is activated by the thermally activating apparatus.
A printer is also being developed which has the thermally activating apparatus in the thermal printer for performing thermal printing onto a heat-sensitive adhesive label and activation of a heat-sensitive adhesive layer in succession.
Such a printer had, for example, an arrangement shown in FIG. 6.
In FIG. 6, reference sign P2 denotes a thermal printer unit; sign C2 denotes a cutter unit; sign A2 denotes a thermally activating unit; and sign R denotes a heat-sensitive adhesive label wound like a roll.
The thermal printer unit P2 includes a printing thermal head 100, a platen roller 101 which is brought into pressure contact with the printing thermal head 100, and a drive system (for example, an electric motor and a gear train or the like), which is not shown, for rotating the platen roller 101.
In FIG. 6, the platen roller 101 is rotated in the direction of D1 (clockwise) to draw out the heat-sensitive adhesive label R; the drawn-out heat-sensitive adhesive label R is subjected to thermal printing, and is then carried out in the direction of D2 (to the right). The platen roller 101 includes a pressurizing means (for example, a coil spring, a leaf spring or the like), which is not shown, by the urging force of which the surface of the platen roller 101 is brought into pressure contact with the thermal head 100.
The heat-sensitive adhesive label R is constructed, for example, as in FIG. 7.
More specifically, base paper 1500 serving as a label substrate has a thermal coat layer 1501 serving as a heat-sensitive color-forming layer, which forms a printable plane, on one side (the surface in FIG. 7), on which a colored print layer 1502 having price frames, characters including units, patterns, or the like printed thereon is formed. The other side (the back in FIG. 7) of the base paper 1500 has a heat-sensitive adhesive layer K coated with a heat-sensitive adhesive having a thermoplastic resin, a solid plasticizer, or the like as the main component.
The printing thermal head 100 and the platen roller 101 operate on the basis of a print signal from a print controller (not shown), thereby allowing desired printing onto the thermal coat layer 1501 of the heat-sensitive adhesive label R.
The cutter unit C2 is used for cutting the heat-sensitive adhesive label R that has been subjected to thermal printing with the thermal printer unit P2 in an appropriate length, including a movable blade 200, a fixed blade 201, or the like which are activated by the primary drive such as an electric motor (not shown). The movable blade 200 is driven in a designated timing by the control of a controller (not shown).
The thermally activating unit A2 is rotated by, for example, a primary drive (not shown), including an inserting roller 300 and an ejecting roller 301 for inserting and ejecting the cut heat-sensitive adhesive label R, wherein a thermally activating thermal head 400 and a platen roller 401, which is brought into pressure contact with the thermally activating thermal head 400, are disposed between the inserting roller 300 and the ejecting roller 301. The platen roller 401 includes a drive system, which is not shown, (such as an electric motor and a gear train), wherein the platen roller 401 is rotated in the direction of D4 (counterclockwise in FIG. 6) to transfer the heat-sensitive adhesive label R in the direction of D6 (to the right in FIG. 6) with the inserting roller 300 and the ejecting roller 301, which rotate in the directions of D3 and D5, respectively. The platen roller 401 includes a pressurizing means, which is not shown, (such as a coil spring and a leaf spring), by the urging force of which the surface of the platen roller 401 is brought into pressure contact with the thermally activating thermal head 400.
Reference sign S indicates an ejection detecting sensor for detecting the ejection of the heat-sensitive adhesive label R. The subsequent printing, transfer, and thermal activation of the heat-sensitive adhesive label R are performed in accordance with the detection of the ejection of the heat-sensitive adhesive label R by, the ejection detecting sensor S.
The thermally activating thermal head 400 and the platen roller 401 are operated by a controller (not shown) in a prescribed timing to activate the heat-sensitive adhesive layer K of the heat-sensitive adhesive label R by heat applied from the thermally activating thermal head 400, thereby exhibiting adhesive force.
After the adhesive force of the heat-sensitive adhesive label R has been exhibited by the thermally activating unit A2 with such an arrangement, indicator labels are adhered to glass bottles for liquor and medicines or plastic cases, or price tags or advertising labels are adhered. Accordingly, there is an advantage in that released sheets (liners) as in conventional general adhesive labels become unnecessary, resulting in reducing cost; and also released sheets which will be waste after use are unnecessary, having an advantage also in view of resource savings and environment.
The printing thermal head 100 of the thermal printer unit P2 and the thermally activating thermal head 400 of the thermally activating unit A2 consume relatively high electric power; accordingly, when both thermal heads are driven at the same time, the power sometimes exceeded the allowable power of the power source of the printer.
Particularly, portable printers used for printing distribution/delivery labels and so on have relatively low allowable electric power because they are driven by a built-in battery as a power source; thus, it was sometimes difficult to operate the printing thermal head and the thermally activating thermal head at the same time.
Accordingly, in the conventional portable printers, first, the printing thermal head 100 of the thermal printer unit P2 is driven to perform printing, and then the thermally activating thermal head 400 of the thermally activating unit A2 is driven to perform thermal activation, thereby covering the consumed power of each thermal head within the allowable power.
However, since the printing thermal head and the thermally activating thermal head are individually operated with a certain time difference, as described above, there was a problem of taking a long period of time until the issue of labels is completed. Particularly, printers carried by delivery servicemen issue labels and the like on the customer""s premises; therefore, which requires to issue labels and so on smoothly in minimum time so as not to keep customers waiting.
The present invention has been proposed to solve the above problems. Accordingly it is an object of the present invention to provide a thermal printer having a thermally activating apparatus for a heat-sensitive adhesive sheet capable of operating a printing thermal head and a thermally activating thermal head in parallel with relatively low allowable power to reduce time until the completion of the issue of labels and so on.
In order to achieve the above object, according to the present invention, there is provided a thermal printer having a thermally activating apparatus for a heat-sensitive adhesive sheet includes: at least a thermally activating apparatus (a thermally activating unit A1) for a heat-sensitive adhesive sheet including at least an activating thermal head 40 for heating to activate a heat-sensitive adhesive layer of the heat-sensitive adhesive sheet R, the heat-sensitive adhesive sheet R having a printable plane on one side of a sheet-like substrate and the heat-sensitive adhesive layer on the other side thereof, and a transfer means for transferring the heat-sensitive adhesive sheet in a designated direction; and a printing thermal head 10 for performing thermal printing onto the printable plane of the sheet-like substrate, the thermal printer including a power-consumption estimating means (a microcomputer M and a designated program) for estimating first electric power consumption required for driving the printing thermal head and second electric power consumption required for driving the activating thermal head of the thermally activating apparatus; a supply-power setting means (the microcomputer M and a designated program) for setting first electric power that can be supplied to the printing thermal head and second electric power that can be supplied to the activating thermal head within the allowable power range on the basis of the first electric power consumption and the second electric power consumption estimated by the power-consumption estimating means; and an energization control means (the microcomputer M and a designated program) for energizing the printing thermal head and the activating thermal head on the basis of the first electric power and the second electric power set by the supply-power setting means.
Consequently, the printing thermal head and the activating thermal head can be driven in parallel within the range of allowable power, thus allowing the reduction of period of time until the completion of the issue of labels and so on formed of the heat-sensitive adhesive sheet R.
The printing thermal head and the activating thermal head include a plurality of dot-like heating devices arranged in parallel; and the power-consumption estimating means counts the number of dots driven in fixed time out of each heating device of the printing thermal head and the activating thermal head, and calculates the first electric power consumption and the second electric power consumption on the basis of the number of dots. Accordingly, the power consumption of the printing thermal head and the activating thermal head can easily be estimated.
Also, the number of dots driven in the fixed time may be counted on the basis of print data supplied from a prescribed print control means and control data of the thermally activating apparatus. This allows the number of dots varying sequentially during the issue of labels and so on to be accurately grasped, so that the power consumption of the printing thermal head and the activating thermal head can be accurately estimated. The power consumption of the activating thermal head is estimated on the basis of the control data of the thermally activating apparatus; however, this is for the purpose of including the case of activating only part (such as the rim or dots arranged at fixed intervals) of the heat-sensitive adhesive sheet in addition to the case of activating the entire surface of the heat-sensitive adhesive sheet.
The supply-power setting means may set the first electric power consumption and the second electric power consumption to the first electric power and the second electric power as they are when the total of the first electric power consumption and the second electric power consumption estimated by the power-consumption estimating means is within the allowable power; and may divide the first electric power consumption and the second electric power consumption into a designated number to set the first electric power and the second electric power when the total of the first electric power consumption and the second electric power consumption estimated by the power-consumption estimating means exceeds the allowable power. Therefore, appropriate electric power can be supplied according to the magnitude of the power consumption of each thermal head; thus, limited allowable power can efficiently be used.
The energization control means may control the first electric power and the second electric power set by the supply-power setting means so as to energize all the heating devices requiring to be driven in the printing thermal head and the activating thermal head at once when the total of the first electric power consumption and the second electric power consumption estimated by the power-consumption estimating means is within the allowable power; and may time-division control the first electric power and the second electric power set by the supply-power setting means so as to energize the heating devices requiring to be driven in the printing thermal head and the activating thermal head with a prescribed time difference when the total of the first power consumption and the second power consumption estimated by the power-consumption estimating means exceeds the allowable power. Therefore, appropriate electric power can be supplied according to the magnitude of the power consumption of each thermal head; thus, limited allowable power can efficiently be used. Particularly, when the total of the first electric power consumption and the second electric power consumption is within the allowable power, energization is controlled such that all the heating devices requiring to be driven in the printing thermal head and the activating thermal head are energized at once, thus allowing the reduction of period of time until the completion of the issue of labels and so on.
The supply-power setting means may set the first electric power consumption and the second electric power consumption to the first electric power and the second electric power as they are when each of the first electric power consumption and the second electric power consumption estimated by the power-consumption estimating means is within the allowable power; and may divide the first electric power consumption or the second electric power consumption into a designated number to set the first electric power or the second electric power when the first electric power consumption or the second electric power consumption estimated by the power-consumption estimating means exceeds the allowable power. Therefore, appropriate electric power can be supplied according to the magnitude of the power consumption of each thermal head; thus, limited allowable power can efficiently be used.
The energization control means may control the first electric power set by the supply-power setting means so as to energize all the heating devices requiring to be driven in the printing thermal head, and then control the second electric power set by the supply-power setting means to energize all the heating devices requiring to be driven in the activating thermal head when each of the first electric power consumption and the second electric power consumption estimated by the power-consumption estimating means is within the allowable power; and may time-division control the first electric power and the second electric power set by the supply-power setting means so as to energize the heating devices requiring to be driven in the printing thermal head or the activating thermal head with a prescribed time difference when the first electric power consumption or the second electric power consumption estimated by the power-consumption estimating means exceeds the allowable power. Therefore, appropriate electric power can be supplied according to the magnitude of the power consumption of each thermal head; thus, limited allowable power can efficiently be used.
Also, the printing thermal head and the activating thermal head may be formed of thermal heads having the same characteristics. Accordingly, the estimation of the power consumption by both thermal heads can easily be performed by the total of the number of dots; thus, setting of supply power and energization control can easily be performed. Also, the common use of parts can reduce manufacturing cost.